TeleGeography: Ethernet VPLS, EoDWDM interest grows, while IP/VPN expansion dips
HISTORICAL SPACE FREQUENCIES. The first satellite to orbit the Earth was Sputnik 1, launched by the Soviets in October 1957. It carried two radio beacons on frequencies of 20.005 and 40.01 MHz. The Soviets continued to use frequencies around 20 MHz and even some around 15 MHz for many subsequent missions. This tends to be used for uplinks of the satellites that downlink in the 137 - 138 MHz band. 2  149.95 - 150.05 MHz. 3  This is used by satellites providing positioning, time and frequency services, by ionospheric research and other satellites.
Most remote sensing satellites, as well as national security assets are placed in LEO. Medium Earth Orbit (MEO) is the region of space around the Earth above LEO (1,240 miles) and below geosynchronous orbit (22,240 miles). In MEO, orbital periods range from about two to 12 hours. The most common use for satellites in this region is for navigation, such as the United Statesâ Global Positioning System (GPS) (12,550 miles), Russian Glonass (11,870 miles) and European Galileo (14,430 miles) constellations.